3com 3031 Instruccion De Instalación
136
C
HAPTER
14: WAN I
NTERFACE
C
ONFIGURATION
By default, the system adopts the protocol approach for link setup.
Enabling/Disabling level detection
If an asynchronous serial interface has been disabled to make level detection, the
system will only detect whether the interface is connected to an external cable and
automatically report the interface state (UP or DOWN) to the user. If the interface
has been enabled to make level detection, the system will detect the DSR signal in
addition to the external cable. The interface will be regarded UP only if the
detected DSR signal is valid. Otherwise, it will be regarded DOWN.
system will only detect whether the interface is connected to an external cable and
automatically report the interface state (UP or DOWN) to the user. If the interface
has been enabled to make level detection, the system will detect the DSR signal in
addition to the external cable. The interface will be regarded UP only if the
detected DSR signal is valid. Otherwise, it will be regarded DOWN.
Perform the following configuration in asynchronous serial interface view.
By default, asynchronous serial interfaces are allowed to make level detection.
Enabling/Disabling loopback
You may enable an asynchronous serial interface to make local loop for the
purpose of testing some special functions.
purpose of testing some special functions.
Perform the following configuration in asynchronous serial interface view.
By default, local loop is disabled.
Configuring MTU
The MTU setting of an asynchronous serial interface can affect the fragmentation
and reassembly of IP packets on the interface.
and reassembly of IP packets on the interface.
Perform the following configuration in asynchronous serial interface view.
Configure an asynchronous serial interface to set up a link with
the protocol approach
the protocol approach
async mode protocol
Configure an asynchronous serial interface to set up a link with
the flow approach
the flow approach
async mode flow
Table 147 Enabling/Disabling an asynchronous serial interface to make level detection
Operation
Command
Enable an asynchronous serial interface to make level detection
detect dsr-dtr
Disable the asynchronous serial interface to make level detection
undo detect dsr-dtr
Table 148 Enabling/Disabling an asynchronous serial interface to make local loop
Operation
Command
Enable an asynchronous serial interface to make local loop
loopback
Disable an asynchronous serial interface to make local loop
undo loopback
Table 149 Setting MTU on an asynchronous serial interface
Operation
Command
Set MTU on an asynchronous serial interface
mtu size
Restore the default MTU
undo mtu
Table 146 Setting the link setup approach applied to an asynchronous serial interface